(9) Instrumentation. Provide a calibrated recording device with an appropriate range or a computerized data acquisition system to measure and record the outputs of the calorimeter and the thermocouple. The data acquisition system must be capable of recording the calorimeter output every second during calibration.
(10) Timing device. Provide a stopwatch or other device, accurate to ±1 second/hour, to measure the time of application of the pilot burner flame.
(c) Test specimens.
(1) Specimen preparation. Prepare and test a minimum of three test specimens. If an oriented film cover material is used, prepare and test both the warp and fill directions.
(2) Construction. Test specimens must include all materials used in construction of the insulation (including batting, film, scrim, tape etc.). Cut a piece of core material such as foam or fiberglass, and cut a piece of film cover material (if used) large enough to cover the core material. Heat sealing is the preferred method of preparing fiberglass samples, since they can be made without compressing the fiberglass ("box sample"). Cover materials that are not heat sealable may be stapled, sewn, or taped as long as the cover material is over-cut enough to be drawn down the sides without compressing the core material. The fastening means should be as continuous as possible along the length of the seams. The specimen thickness must be of the same thickness as installed in the airplane.
(3) Specimen Dimensions. To facilitate proper placement of specimens in the sliding platform housing, cut non-rigid core materials, such as fiberglass, 12-1/2 -inches (318mm) wide by 23-
739 inches (584mm) long. Cut rigid materials, such as foam, 11-1/2 ±1/4 -inches (292 mm ± 6mm) wide by 23-inches (584mm) long in order to fit properly in the sliding platform housing and provide a flat, exposed surface equal to the opening in the housing.
(d) Specimen conditioning. Condition the test specimens at 70 ±5 degree F (21 ± 2 degree C) and 55% ± 10% relative humidity, for a minimum of 24 hours prior to testing.
(e) Apparatus Calibration.
(1) With the sliding platform out of the chamber, install the calorimeter holding frame. Push the platform back into the chamber and insert the calorimeter into the first hole ("zero" position).
See figure 7. Close the bottom door located below the sliding platform. The distance from the centerline of the calorimeter to the radiant panel surface at this point must be 7-1/2-inches ± 1/8 (191 mm ± 3). Prior to igniting the radiant panel, ensure that the calorimeter face is clean and that there is water running through the calorimeter.
(2) Ignite the panel. Adjust the fuel/air mixture to achieve 1.5 BTUs/ft2 -second ± 5% (1.7 Watts/cm2 ± 5%) at the "zero" position. If using an electric panel, set the power controller to achieve the proper heat flux. Allow the unit to reach steady state (this may take up to 1 hour).
The pilot burner must be off and in the down position during this time.
(3) After steady-state conditions have been reached, move the calorimeter 2-inches (51 mm) from the "zero" position (first hole) to position 1 and record the heat flux. Move the calorimeter to position 2 and record the heat flux. Allow enough time at each position for the calorimeter to stabilize. Table 1 depicts typical calibration values at the three positions.
Table 1.-Calibration Table Position BTU's/ft 2 sec Watts/cm 2 "Zero" Position 1.5 1.7 Position 1 1.51-1.50-1.49 1.71-1.70-1.69 Position 2 1.43-1.44 1.62-1.63
(4) Open the bottom door, remove the calorimeter and holder fixture. Use caution as the fixture is very hot.
(f) Test Procedure.
(1) Ignite the pilot burner. Ensure that it is at least 2-inches (51 mm) above the top of the platform. The burner must not contact the specimen until the test begins.
(2) Place the test specimen in the sliding platform holder. Ensure that the test sample surface is level with the top of the platform. At "zero" point, the specimen surface must be 7-1/2-inches ± 1/8-inch (191 mm ± 3) below the radiant panel.
(3) Place the retaining/securing frame over the test specimen. It may be necessary (due to compression) to adjust the sample (up or down) in order to maintain the distance from the sample to the radiant panel (7-1/2 -inches ± 1/8 -inch (191 mm± 3) at "zero" position). With film/fiberglass assemblies, it is critical to make a slit in the film cover to purge any air inside.
This allows the operator to maintain the proper test specimen position (level with the top of the platform) and to allow ventilation of gases during testing. A longitudinal slit, approximately 2- inches (51mm) in length, must be centered 3-inches ± 1/2 -inch (76mm±13mm) from the left flange of the securing frame. A utility knife is acceptable for slitting the film cover.
(4) Immediately push the sliding platform into the chamber and close the bottom door.
(5) Bring the pilot burner flame into contact with the center of the specimen at the "zero" point and simultaneously start the timer. The pilot burner must be at a 27 degree angle with the sample and be approximately 1/2-inch (12 mm) above the sample. See figure 7. A stop, as shown in figure 8, allows the operator to position the burner correctly each time.
Figure 8 - Propane Burner Stop 741
(6) Leave the burner in position for 15 seconds and then remove to a position at least 2-inches (51 mm) above the specimen.
(g) Report.
(1) Identify and describe the test specimen.
(2) Report any shrinkage or melting of the test specimen.
(3) Report the flame propagation distance. If this distance is less than 2-inches, report this as a pass (no measurement required).
(4) Report the after-flame time.
(h) Requirements.
(1) There must be no flame propagation beyond 2-inches (51 mm) to the left of the centerline of the pilot flame application.
(2) The flame time after removal of the pilot burner may not exceed 3 seconds on any specimen.] 1195 – 1200. [RESERVED]
743 1201. APPENDIX F, PART VII, DID NOT EXIST PRIOR TO AMENDMENT 25-111.
1202. APPENDIX F, AMENDMENT 25-111, Effective September 2, 2003. This amendment added Part VII.
[PART VII-TEST METHOD TO DETERMINE THE BURNTHROUGH RESISTANCE OF THERMAL/ACOUSTIC INSULATION MATERIALS.] [Use the following test method to evaluate the burnthrough resistance characteristics of aircraft thermal/acoustic insulation materials when exposed to a high intensity open flame.
(a) Definitions.
Burnthrough time means the time, in seconds, for the burner flame to penetrate the test specimen, and/or the time required for the heat flux to reach 2.0 Btu/ft2 sec (2.27 W/cm2) on the inboard side, at a distance of 12-inches (30.5 cm) from the front surface of the insulation blanket test frame, whichever is sooner. The burnthrough time is measured at the inboard side of each of the insulation blanket specimens.
Insulation blanket specimen means one of two specimens positioned in either side of the test rig, at an angle of 30 degree with respect to vertical.
Specimen set means two insulation blanket specimens. Both specimens must represent the same production insulation blanket construction and materials, proportioned to correspond to the specimen size.
(b) Apparatus.
(1) The arrangement of the test apparatus is shown in figures 1 and 2 and must include the capability of swinging the burner away from the test specimen during warm-up.
Detail A 125" (1219 mm) Detail A (127 mra) (32 mm) (127 mm) 36" (914 mm) 34" (864 mm) 107 moly (203 mm) Detail B 24"° (610 mm) All Horizontal Hat-shaped Stringers Bolted to Vertical Formers Detail B
0.75" (19 mm) 10' - (25 mm) 015" (13 mm) All Material 0125" (3 mm) Thickness Except Center Vertical Former, 0.250" (6 mm) Thick Figure 1 - Burnthrough Test Apparatus Specimen Holder
(2) Test burner. The test burner must be a modified gun-type such as the Park Model DPL 3400.
Flame characteristics are highly dependent on actual burner setup. Parameters such as fuel 744
745 pressure, nozzle depth, stator position, and intake airflow must be properly adjusted to achieve the correct flame output.
Figure 2 - Burnthrough Test Apparatus
(i) Nozzle. A nozzle must maintain the fuel pressure to yield a nominal 6.0 gal/hr (0.378 L/min) fuel flow. A Monarch-manufactured 80[degree] PL (hollow cone) nozzle nominally rated at 6.0 gal/hr at 100 lb/in2 (0.71 MPa) delivers a proper spray pattern.
(ii) Fuel Rail. The fuel rail must be adjusted to position the fuel nozzle at a depth of 0.3125-inch (8 mm) from the end plane of the exit stator, which must be mounted in the end of the draft tube.
(iii) Internal Stator. The internal stator, located in the middle of the draft tube, must be positioned at a depth of 3.75-inches (95 mm) from the tip of the fuel nozzle. The stator must also be positioned such that the integral igniters are located at an angle midway between the 10 and 11 o'clock position, when viewed looking into the draft tube. Minor deviations to the igniter angle are acceptable if the temperature and heat flux requirements conform to the requirements of paragraph VII(e) of this appendix.
(iv) Blower Fan. The cylindrical blower fan used to pump air through the burner must measure
5.25-inches (133 mm) in diameter by 3.5-inches (89 mm) in width.
(v) Burner cone. Install a 12 +0.125-inch (305 ±3 mm) burner extension cone at the end of the draft tube. The cone must have an opening 6 ±0.125-inch (152 ± 3 mm) high and 11 ± 0.125-inch (280 ± 3 mm) wide (See figure 3).
(vi) Fuel. Use JP-8, Jet A, or their international equivalent, at a flow rate of 6.0 ± 0.2 gal/hr
(0.378 ± 0.0126 L/min). If this fuel is unavailable, ASTM K2 fuel (Number 2 grade kerosene) or ASTM D2 fuel (Number 2 grade fuel oil or Number 2 diesel fuel) are acceptable if the nominal fuel flow rate, temperature, and heat flux measurements conform to the requirements of paragraph VII(e) of this appendix.
(vii) Fuel pressure regulator. Provide a fuel pressure regulator, adjusted to deliver a nominal
6.0 gal/hr (0.378 L/min) flow rate. An operating fuel pressure of 100 lb/in2 (0.71 MPa) for a nominally rated 6.0 gal/hr 80 degree spray angle nozzle (such as a PL type) delivers 6.0 ± 0.2 gal/hr (0.378 ± 0.0126 L/min).
1550" (394 mm) Sur — 4- (127 mm
• 19/32" (15 mm) Spaces 10 Degree bends on Broken Line (305 mm) 120 (318 mm) 12,50" 2764" (11 mm) Spaces
- 050" (13 mm) . 050" (13 mm)
• Bolts (25 m) * LƠ°
12.25 Connection flange (311 minu) 110° (279 mm) (152 m)
- 425" (108 mm) Note: Ouchalf of tube * (05 a e) Matetial: 0050* (13 nut) stainless steel extension shown. Second 750 half mates at spotweld overlaps (191 man) Figure 3 - Burner Draft Tube Extension Cone Diagram 747
(3) Calibration rig and equipment.
(i) Construct individual calibration rigs to incorporate a calorimeter and thermocouple rake for the measurement of heat flux and temperature. Position the calibration rigs to allow movement of the burner from the test rig position to either the heat flux or temperature position with minimal difficulty.
(ii) Calorimeter. The calorimeter must be a total heat flux, foil type Gardon Gage of an appropriate range such as 0-20 Btu/ft 2 -sec (0-22.7 W/cm2), accurate to ± 3% of the indicated reading. The heat flux calibration method must be in accordance with paragraph VI(b)(7) of this appendix.
(iii) Calorimeter mounting. Mount the calorimeter in a 6- by 12- ± 0.125-inch (152- by 305- ± 3 mm) by 0.75 ± 0.125-inch (19 mm +/ -3 mm) thick insulating block which is attached to the heat flux calibration rig during calibration (figure 4). Monitor the insulating block for deterioration and replace it when necessary. Adjust the mounting as necessary to ensure that the calorimeter face is parallel to the exit plane of the test burner cone.
6 in x 12 in x 3/4 in 1-in (25 mm) (152 x 305 x 19 mm) dia hole for Marinite block calorimeter mounting 1 in (25 mm) 6 ‡ 1/8 in (152 # 3 mm) 3 ÷ 1/8 in (76 * 3 mm) 12 ÷ 1/8 in (305 = 3 mm) Side View 3/4 in Burner! Cone (19 mm) 1 in (25 mm) dia - 4 * 1/8 in (102 ‡ 3 mm) Water-cooled calorimeter Steel angle 1 x 1 x 1/8 in Rack mounts to (25 x 25 x 3 mm) test frame Top View Figure 4 - Calorimeter Position Relative to Burner Cone 749